Floyd Mayweather says he has not agreed to face Tenshin Nasukawa in an official bout and had "never heard" of the Japanese kickboxer until this week.

Mayweather, 41, says he had only been asked to compete in a non-televised event for "wealthy spectators".

"Once I arrived to the press conference, my team and I were completely derailed," said Mayweather.

"We should have put a stop to it immediately.

"I can assure you that I too was completely blindsided by the arrangements that were being made without my consent nor approval. I was hesitant to create a huge disturbance by combating what was being said and for that I am truly sorry."

The unbeaten American extended his record to 50 wins in August of 2017 with victory over UFC star Conor McGregor in a bout which earned him a reported $300m (£228m).